Pbocess of proportioning sand aud water bop



Jan. 10, 1928. LESQOM c. s. JOHNSON PROCESS OF PROPORTIONING SAND ANDWATER FOR CONCRETE Filed April 19. 1926 15 L343 2 T 5 9 v I 5 if 2'5%%J/ mm M MW Patented Jan. 10, 1928.

UNITED STATES'ATENT OFFICE.

UHARLE$ S. JOHNFB'UN, 01* GHAMPILIGN, ILLINOIEE.

PROGEEB 0F PROPURTIONTNG? SAND AND WATER FOR CONCRETE.

The invention relates generally to the art of making concrete and moreparticularly to a method for proportioning the total amount of water inthe min.

It is the object of the invention to provide a new and improved processfor proportioning the total amount of water in a concrete mix, that willcompensate for the normal moisture content of the sand.

It is another object ot the invention to provide an improved process forproportioning the total water in a concrete mix which is readily adaptedto field worlt.

It has been recognized that the strength of concrete depends largelyupon the total amount of water in the min, and it follows that accuratecontrol of the total water in eluded in the mix is highly essential toob tain concrete of uniform strength.

The methods heretofore used for proportioning the water in the mix havenot given uniform results. In the processes used here tofore wherein thesand is measured by volume and then introduced into a concrete mix witha separately proportioned unit of water, variations in the normalmoisture content of the sand. have caused variations in the total waterin the min. Attempts have been made to control accurately the amount ofwater introduced into the mix but no process has been advanced wherebythe total water'could be controlled satisfactorily withoutadjustment tocompensate tor unap parent variations in the compaction of the sand.

Changes in the moisture content in commercial sand alter the apparentvolume of the sand due to the resulting changes in bulking, but do notalter the absolute volume of the sand. The changes in apparent volumeare not directly proportional to the changes in normal moisture contentthroughout the full range of possible moisture content in the sand.However, an anal ysis of the bulking characteristics of com mercial sandhas disclosed that the absolute volume of sand in equal apparent volumesof moist sand is quite constant within a certain range of moisturevariation, and

Serial No. 103 183.

practically uniform absolute volumes independent of the normal moisturecontent within this range.

I utilize these facts in providing a process for proportioning the totalamount of water for a concrete mix, the process consisting generally ofmeasuring a predetermined volume of normally moist commercial sand andthen combining with that sand a quantity of water such. that thecombined sand and total water equals a predetermined volume.

For the purpose of illustrating more clearly the operation of theprocess I have illus trated in the accompanying drawings an ap paratusadapted toutilize the process, together with diagrammatic sectionalviews of the apparatus at various stages in the proc lit is to beunderstood, however that the term of the apparatus and the arrangementof the parts may be varied at will without departing from the spirit andscope oi the invention as defined by the appended claims.

In the drawings:

Figure 1 is an elevational view of a volumetric measuring device.

Fig. 9. is a sectional view thereof at one stage of the process.

Fig. 3 is a similar view at a later stage.

Referring to the drawings, the device se lected for purposes ofillustration comprises a sand bin A and an adjustable measuring hopperB. The sand bin may be suitably supported by any desired means (notshown). This bin has a circular discharge opening 1 at the bottomthereof and is provided with a gate 2 pivoted at 3 to oscillate about avertical axis. A handle ti: on the gate serves as a means to operate thegate.

The measuring hopper B comprises an upper conical portion 5 and a lowercontainer 6 which is generally cylindrical in form but which hasinwardly sloping sides 7 at the bottom converging to define a circulardischarge port 8, thereby to insure complete discharge of material fromthe hopper. The upper portion 5 is herein shown supported from the bin Aby means of a plurality of integral brackets 9 and chains 10 which areattached at their opposite. ends to the brackets and to the bin A. Thecontainer is adjustable relative to the upper portion 5 f the hopper topermit of adjustment of i volumetric content of the l For the containerin shown suspended from the brackets 9 by means of chains 11, andadjustable screw devices 12 having hooked portions 13 are provided oneach bracket to receive the free end of a chain. Should it be desired toadjust the volume of the hopper to a greater extent than that providedfor by the screw devices. a lower link on each chain may be caught overthe hooks 13. r V

Agate "1 having :1 water tight gasket 1% is provided to control thedischarge opening 8 of the hopper; This gate is carried on an armpivotally supported intermediate its endsat i6 on a bracl-zet 17 whichis secured rigidly to the container 6. The end 18 of this arm' 'ispivoted to an outstanclingilug 19 'onthe gatel' As herein illi.itratedthe arm is operable by means of a hand lever 20 pivoted-at 21 onthe bracket 17, and a toggle link 22 connecting the adjacent ends of thelever 20and'arnr15. Thum in its. closed positionthe gate leisheld'locked by the toggle device: I

' In'the apparatus illustrated in the draw ings--meansis provided tocombine water fof'commercial' sand the hopper may be adjustedinaccordance with asuitable scale (not shown)-to' measure this volume: Ifa predetermined quantityjof compacted sand is desired anda quantity ofnormally moist bulk sandis to' loe measured which will yield anequivalent amount of compacted sand,

the volume of themeasuring hopper may be setby experiment as follows "A'hopperfulofloose 11101813 sand is disclia-rged unto a calibratedmeasure and therein. compacted by t a rnping, ro'dding Oll othersuitable methods Should this batch oflfoose o sand yield". lefssthan thedesired volume. of

compactecl-fsand,- the hopper B is adjusted to 'measurea greatervolumethan before and vrc'efversa-l By Zt 'SGllGS of such GXPQI'IIHGHJESthesvo'lume of the hopper B is adjusted so as measure a quantity 10floose normally compacted sand.

' rn oist sandcontainingthe' desired volumeof 'Withthe hopper' properlyadjusted it is then necessary to set the overflow 25 at a glevel wherebythe water added, combined .wi'th'the moisture in'the sand, gives aconcretemix of the desired consistency. A field method well adapted fordetermining the proper level of the overflow, consists in making aseries of experimental batches of concrete with the overflow set atdifferent levels, until concrete of the desired consistency is obtained.Thus with the gate l-lclosed, the gate 1 on the bin A is opened byoperating the handle whereupon sand from the bin discharges into thehopper until the hopper is full shown in Fig. llv closing the gate 1 thesand in the bin cut oil from the sand in the hopper, thus lcaviru, thedc sired volume of loose sand in the hopper.

Water is then admitted from the supply line by opening the hive 2i,until the water in the hopper reaches the height oi? the overflow asshown in'l ip. ll. This point is fienorally determined by allowing somewater to discharge over the overflow. The valve 241- is then closed, andthe experiment nl bal ch of combined sand and water is used to make abatch of concrete. ll the consistency of: the resulting" mix is otherthan that desired, the nuts on the bolts 26 are loosened and th overflowis raised or lowered depending upon whether the concrete was too dry orwet, By a series of such experimental hatii'hcs the overflow may beadjusted to a level which will provide the water necessary for thedesired consistency of concrete providing the absolute volume of eachbatch oi? the ncnrcas uredloose SilllCldOES not vary. lVith the volumeof the hopper B adjusted and the over flow 25 set at the selected level,the process consists of the following steps. First the predeterminedvolume of normally moist sa ndis measured by filling the hopper from thebin A. Water is then'admitted from the pipe 23 until it reaches thelevel of the overflow whereupon the valve is closed. The mass ofcombined sand and water is then ll-SeCl'il'l'Inl-lill'lg a batch ofconcrete.

It is apparent that by this process the moisture introduced into thecontainer as moi sturc in the sand, becomes apart oi the total waterandthat the total water inthe container is complementary in volume tothe absolute volume of the sand. Inasmuch as the variation in absolutevolume of sand measured by apparent volumes is less than the moisturevariation, within the range hcrcinbe'lorc mentionechit will-be apparentthat the variation in total water measured by this process will be lessthan that encounteredwhen water and moist sand are measured inde---pendently and later combined in a mix.

The process isparticularly well adapted i or use with apparatus ofsimple construc' tion and because of its ease of operation readily lendsitself to field work. When used withthe apparatus described herein, andthis apparatus has once been calibrated. it ismerely necessary for anoperator to open the gate on the sand bin and thereby discharge sandinto the hopper until the l ll volume.

sand stops flowing, then by closing the gate he strikes oil the sand tothe predetermined The valve in the water line is then opened and Waterpermitted to flow into the hopper until some of it overflows the outlet,whereupon by closing the valve the combined sand and Water is ready tobe mixed with the proper proportions of cement and stone and may bedischarged through the gate on the hopper.

I claim as my invention:

1. A process for proportioning the total Water in a concrete mix whichcomprises measuring a predetermined volume of normally moist sand andcombining water with said measured sand until the combined sand andtotal Water equals a second predetermined volume.

2. A process for proportionintl the water in a concrete mix whichcomprises placing a premeasured quantity of normally moist sand in acontainer and flowing Water up- Wardly through the sand to apredetermined level.

3. In a process for making concrete mixtures, the step of proportionin gthe total Water as a complementary volume to the absolute volume ofpremeasured normally moist bulk sand.

4.. The process of making concrete mixtures which consists in measuringby apparent volume a quantity of normally moist commercial or bulk sandsufficient to equal substantially a predetermined absolute volume, andthen adding water to said measured sand to produce a predeterminedcombined volume.

5. In concreteconstruction, the process of measuring the sand and Waterfor the mix which consists in introducing moist bulk sand into a hopperhaving a Water outlet located at a predetermined level, striking oil theexcess sand at a predetermined point above said water outlet, admittingWater to the hopper from a point below said outlet until a quantity isfree to run ott through the outlet, and finally discharging the combinedsand and water from the hopper.

6. The process of making concrete which includes a step of combiningwater and a quantity of bulk sand having a variable moisture contentuntil the combined elements attain a predetermined volume as determinedby the predetermined proportions of the elements to constitute the mix.

In testimony whereof, I have hereunto affixed my signature.

CHARLES S. JOHNSON.

